What you need to know

Working at night disrupts the circadian rhythm and can lead to the accumulation of a sleep debt, impairing performance and health

Full circadian adaptation to night shift work is not possible in the short term

Night shift workers should be aware of reduced performance during critical tasks and on the journey home

Sources and selection criteria

We selected published guidance on sleep and shift work from the National Institute for Health and Care Excellence (NICE) and the Royal Colleges of Physicians and Anaesthetists. We then searched PubMed and Cochrane databases (to May 2017) for observational studies, randomised controlled studies, meta-analyses, and systematic and narrative reviews relating to the health consequences of shift work and for each proposed sleep intervention given in table 1. Priority was given to randomised controlled trials and meta-analyses, but given the interdisciplinary nature of sleep and shift work, and the overall quality of evidence, we also considered observational studies and grey literature from aviation and heavy industries, as well as published expert opinion.

Night shift work occurs during the period of the sleep-wake cycle (“circadian phase”) programmed for sleep. Alertness, cognitive function, psychomotor coordination, and mood all reach their lowest point between 3 and 5 am1 After the shift, workers must rest during the circadian phase least conducive to sleeping,2 which compounds fatigue and can lead to chronic sleep disturbance.3 A recent systematic review linked night shift work with an increased risk of sleep loss, occupational accidents, obesity and weight gain, type 2 diabetes, coronary heart disease, and breast, prostate, and colorectal cancers.4 In a 2017 survey of 2231 UK trainee anaesthetists, more than 70% reported that fatigue affected their physical and psychological wellbeing. Fifty seven per cent described an accident or near-miss travelling home from night shifts.5